1. Field of the Invention
This invention relates to a mat for pressure measurement and a body information acquisition device used thereof.
2. Description of the Related Art
Conventionally, an air mat comprising the sleep cycle sensing device illustrated in Japanese Patent No. 2000-215 is disclosed as a mat for pressure measurement. The air mat comprises an air tube and the inside of the air tube is filled with air in a similar manner to the air mat. A sleep cycle sensing device detects the air pressure and the change amounts in the air tube by the respectively separate sensors, distinguishes whether or not a subject is on an air mat based on the detected air pressure, and measures a subject's body motion based on the change amount of air pressure. Then, a subject's sleep state is estimated based on the measurement result of the body motion.
In the above-mentioned sleep cycle sensing device, since it was not taken into consideration about the type of body motion such as whether a subject's body motion was rolling over or others, the distribution of pressure applied to an air mat could not be measured, even if the change or strength of pressure applied to an air mat could be measured. For this reason, when even the distribution of pressure applied to an air mat by using the above-mentioned air mat was measured, a plurality of detection units in the air mat and the sensor for measuring the pressure applied to the air mat for every detection units were required to be provided.